This invention relates generally to all looms allowing considerable irregularities in motion and in which the inertial of the kinematics, led back to a constant speed component such as the driving shaft, has a perceptibly sinusoidal behavior.
The invention relates more especially to looms with stiff weft inserters which have imparted thereto a to-and-fro movement, and in which looms the weft is introduced and drawn into the shed by long needles perceptibly stiff over their whole lengths, as well as to ribbon looms in which the insertion is taken care of by short needles fixed on one end of a flexible drive ribbon.
In the course of one cycle in operation of shuttleless looms of the type in question, the kinematics introduce, at the level of the crankshaft controlling the sley, very large variations in speeds due essentially to the large variations in the inertia, led back to the motor or to the crank, of the control mechanisms of the sley and of weft insertion. The speed variations are always accompanied by very harmful large vibrations, as much in the weaving range as the level of the supplementary mechanical influences which they develop. The fitting on of a flywheel of sufficient inertial would raise the problem of the braking of a large mass in motion.